Yeah, +1 on that.
I think that there is not one single type of sound that makes certain genre of music the best. It still comes down to personal preference and two guys can go for two completely different signatures for exactly the same music.
Again I don't see why quoting your experience with metal or what someone considers metal gives someone more credibility but that's just me.
I for one have absolutely no problem listening to stuff like Whitesnake, Deep Purple, Dio, Black Sabbath etc. on the ety er4s and I like it more than the vsonics. As I said, it's personal preference - someone might want something really V-shaped with a lot more bass like a tf10, for instance, while someone like me can go with something more balanced with less bass.
That personal preference doesn't really make someone lacking any understanding or knowledge in metal and rock music. I've been to concerts of all these bands and I know how they sound live. Now, these vsonics are great in the sense that they are smooth and pretty forgiving on badly recorded and mastered stuff and overall are more relaxing and non-fatiguing to listen to but there always will be someone who finds them not clear enough, or lacking bass, or having too much bass, or lacking in speed, or being sibilant etc., so if someone has the VSD1 or VSD1S and is wondering if he should get the other one - I would say that if you can sell yours without much loss and you really want to hear the other one out of curiosity, then go for it, otherwise you might want to look for a different iem.
I agree with you and blupblup, everyone's taste is different. If it sounds good to you that's all that matters. I think Vsonic is one of the better IEM companies but there and it is my personal favorite. I can't wait for there new stuff to come out.